Prevalence of bovine milk pathogens in Azorean pastures: mobile versus fixed milking machines

Abstract

The aims of the present study were (1) to evaluate the influence of using mobile (n=47) or fixed (n=45) milking machines in Azorean herds on the apparent prevalence of several milk pathogens in bulk tank milk (BTM) and (2) to determine whether separated subclinical mastitic cows can serve, in real time, as predictors of milk pathogen prevalence for the remaining animals at the herd level. The use of a mobile or fixed milking machine influenced (P≤0.05) the prevalence of Staphylococcus aureus (72.3 per cent; n=34 v 51.1 per cent; n=23, respectively) and Klebsiella species (46.8 per cent; n=22 v 26.7 per cent; n=12, respectively). S aureus (95 per cent CI OR 1.1 to 6.0) and Klebsiella species (95 per cent CI OR 1.0 to 5.8) were 2.5 times more likely to increase in the BTM of herds using mobile milking machines. The prevalence of coagulase-negative staphylococci (100 per cent; n=92), Escherichia coli (75.0 per cent), Corynebacterium bovis (57.6 per cent), Enterococcus species (55.4 per cent), Streptococcus dysgalactiae (51.1 per cent), Streptococcus uberis (41.3 per cent), Actinomyces pyogenes or Peptostreptococcus indolicus (41.3 per cent) and Streptococcus agalactiae (32.6 per cent) in BTM remained similar among the herds. κ coefficients were always <0.70, indicating intra-herd disagreement of the prevalence of milk pathogens between BTM and separated milking cows. Milking hygiene should be improved in pastures, focusing specifically on herds that use a mobile milking machine. The segregated cows at milking time are not good predictors of milk pathogens in BTM.

Staphylococcus aureus, Escherichia coli, and Klebsiella spp. prevalence in bulk tank milk of Colombian herds and associated milking practices

“…Inadequate hygiene practices can increase the probability of isolating S. aureus and consequently increase the SCC in the BTM [25,51], which is consistent with our findings, where performing an adequate milking protocol allowed for reducing the average SCC in herds. In this study, the practices that were found to be associated with the decrease in SCC were the use of other hand disinfection products (i.e., alcohol, chlorhexidine, and lactic acid), hand disinfection between cows, and forestripping.…”

“…However, more studies are needed to understand this possible link. Although the milking system characteristics are not the same, these findings are consistent with a study that found a higher probability of isolating the pathogen in herds that used mobile milking machines in Portugal [ 51 ]. At least in Colombia, this could be related to the variability of the pastures and paddock conditions that can be affected by rainfall and thus influence the incidence of pathogens and, therefore, SCC [ 25 ].…”

Detection and Molecular Characterization of Bovine Leukemia Virus in Egyptian Dairy Cattle

“…Interestingly, the milking system of this farm depends on using a limited number of common portable milking machines, thus lacking sufficient cleaning during milking between individual cows. Therefore, the likelihood of bovine milk pathogen transmission is higher in herds using mobile milking machines than that in herds using fixed milking machines, as previously demonstrated ( 52 ). In addition, BLV has a broad tropism to the mammary tissue ( 53 ) and the milk or milk cells of infected cattle could be a source of infection ( 12 , 54 , 55 ).…”

Streptococcus agalactiae is not always an obligate intramammary pathogen: Molecular epidemiology of GBS from milk, feces and environment in Colombian dairy herds

“…However, GBS is still a threat for many countries, particularly for those with developing dairy industries such as Colombia and Brazil, where herd prevalence is 40% and 60%, respectively [12, 13]. Other countries with high herd-level GBS prevalence include Spain (36%) [14], Germany (29%) [15], and China (92%) [16]. Some countries that had successfully controlled GBS, have reported the re-emergence of this pathogen, e.g.…”